Amid the rise of green rhetoric and with fuel prices under scrutiny, biofuels have become a major topic in the energy transition . From pumps offering "100% renewable" gasoline and diesel to research projects exploring new uses for agricultural waste, the feeling is that these fuels could be a fast track to decarbonizing transportation.
However, when you scratch beneath the surface, the picture is considerably more complex. Numerous analyses warn that biofuels have a rather limited role , especially with regard to private vehicles, while in Spain and other European countries, projects are multiplying to make better use of agricultural byproducts and move towards advanced biofuels for decarbonization and higher value-added bioproducts.
A limited role for biofuels in everyday mobility
In recent summers, many people have opted to fill their tanks with fuels labeled as 100% renewable , believing that this choice directly contributes to curbing the climate crisis. The logic is understandable: transportation is the only major sector where greenhouse gas emissions continue to rise, and switching fuels seems like a simple and quick solution.
Organizations like ECODES, however, insist that not all solutions have the same impact . Their recent analysis concludes that biofuels should play a very limited role in the energy transition and that, in the case of cars, they are not the preferred option. For everyday use, they point to active mobility (walking, cycling), public transport, and, when there is no alternative, electric cars as more efficient options for both money and the environment.
Recent geopolitical instability has also served to test the supposed advantage of these fuels. Faced with shocks stemming from international conflicts, biofuels marketed as renewables have shown price behavior very similar to that of fossil gasoline and diesel . In other words, far from protecting consumers from price increases, they have become practically in parallel.
The underlying issue is that Spain, and much of Europe, lacks sufficient domestic resources to support a massive expansion of biofuel use in light vehicles. In Spain's case, the vast majority of necessary raw materials are already imported from third countries, perpetuating a high level of external dependence and once again exposing the economy to the fluctuations of the global market.
Dependence on raw materials and effects on the territory
One of the most concerning aspects is the origin of the raw materials used. In 2024, across the biofuels sector, a significant portion of the inputs came from crops such as soybeans, palm, rapeseed, and sunflowers , in addition to corn and sugarcane in the case of bioethanol. These crops compete directly with food production for land and water.
Soybeans, for example, have become a major driver of deforestation globally . Every hectare used to fill reservoirs is one less hectare available for growing food, in a context where food security is perceived as increasingly fragile. The rising cost of agricultural commodities, linked to energy demand, ends up hitting vulnerable regions the hardest, both within and outside of Europe.
In the aviation sector, the use of specific biofuels such as HEFA (a type of sustainable jet fuel) clearly illustrates the challenges of this model. A significant portion of these products is imported from countries like Indonesia, Malaysia, and China, meaning that the transport of the raw materials themselves adds a considerable volume of emissions to the supply chain, in addition to perpetuating dependence on distant sources.
Adding to this mix are the debates surrounding land-use change —that is, the transformation of forests or other ecosystems into agricultural land—and the pressure these crops exert on water and soil. Although the emission reduction figures that are usually reported can be very high percentages, experts point out that many estimates do not incorporate all the relevant factors of the life cycle , from the energy required for the industrial process itself to potential fraud regarding the origin of the oils used.
From a European perspective, these issues have reached the EU institutions. In recent debates, the European Parliament has considered proposals to limit or ban the use of certain high-risk raw materials in biofuels , such as soy linked to deforestation, although some of these restrictions have ultimately not been approved, keeping the political and social debate open.
Air pollution and health: more modest benefits than expected
Beyond climate and geopolitics, air quality is another key issue when analyzing the role of biofuels. Part of the appeal of these fuels lies in the idea that they are not only more climate-friendly, but also cleaner for the health of those who breathe city air.
However, available data indicate that when burned in conventional engines, biofuels continue to emit concerning air pollutants . Substances associated with lung infections, chronic respiratory problems, and other illnesses remain present at concentrations similar to those found in traditional gasoline and diesel, especially in urban environments with heavy traffic.
In strictly climate terms, the emission reduction figures that are often cited—sometimes approaching 90%—depend heavily on the type of raw material, its origin, and the methodological approach used. Thus, not all biofuels offer the same level of CO2 savings : products like bioethanol derived from food crops can fall significantly short of these figures, while more advanced fuels, such as certain HEFAs derived from residual fuels, come closer to the advertised percentages.
All of this reinforces the idea that there is no single "neutral" or universally beneficial biofuel , but rather a wide range of products with very different impacts. In this context, numerous voices in the scientific and environmental fields emphasize that its primary role should be reserved for sectors where electrification is particularly complex, such as certain segments of air, sea, or heavy transport, while promoting direct energy demand reduction and electrification where it is technically and economically feasible.
Research in Spain: from agricultural waste to advanced biofuel
While the debate intensifies regarding the limitations of first-generation biofuels, Spain is taking steps to make better use of agro-industrial waste and byproducts . A significant example is the work being carried out by the Biofuels and Bioproducts R&D Center in Villarejo de Órbigo (León), which is part of the Agrarian Technological Institute of Castile and León (Itacyl).
This center currently coordinates several European projects in collaboration with universities, technology centers, companies, and organizations in Spain and Portugal, with the aim of transforming agricultural and livestock byproducts into biofuels and higher value-added bioproducts . Among the most noteworthy initiatives are Biovino II and Fibnat, with budgets of approximately two million and slightly more than 1,2 million euros, respectively, representing a significant investment in the region.
Biovino II focuses on the wine sector and aims to give a second life to grape pomace, lees, and other winery waste . Through various technologies, the project explores their conversion into products such as bioalcohols, organic acids, polyphenols, and biomethane, fully embracing the principles of the circular economy. In this way, what was once considered waste becomes a potential source of energy and compounds of interest to industry.
Fibnat, for its part, is studying the use of natural fibers from hops, hemp, and even wool , with a view to developing new materials, particularly in the construction sector. While its primary focus is not fuel, this project aligns with the same strategy of diversifying bioproducts derived from biomass and reducing dependence on fossil fuels in various industrial sectors.
The Regional Ministry of Agriculture, Livestock, Rural Development, and Environmental Policy of Castile and León has emphasized the importance of ensuring that these R&D&I projects do not remain confined to the laboratory . The stated objective is to strengthen the direct transfer of knowledge to farms, industries, and businesses, so that the solutions developed translate into greater competitiveness, the opening of new markets, and the generation of added value in rural areas.
Currently, the Biofuels and Bioproducts R&D Center is involved in several projects with hundreds of thousands of euros in funding, always in cooperation with other stakeholders in Spain and Portugal. The aim is to consolidate an innovation ecosystem around biomass and agri-food waste , leveraging the region's access to raw materials, technical expertise, and a robust agri-food industry that can drive this transformation.
Overall, the landscape surrounding biofuels in Spain and Europe presents both positive and negative aspects. On the one hand, there are solid initiatives to convert agricultural waste into energy and advanced materials , boosting the circular economy and rural development. On the other hand, significant doubts persist regarding the role conventional biofuels should play in daily transportation, their actual capacity to reduce emissions, their effects on health, and their impact on food security and deforestation. Public debate and the political decisions made in the coming years will be crucial in ensuring that these fuels are used where they truly add value, and not as a seemingly easy solution that simply shifts problems from one area to another.
